Yup, pellets are good, but some brands are better than others. Bloodworms make a good treat (though I've heard some disagree and say they are not very nutritious). Its also good to fast them once a week.

I feed Topfin, Topfin Color Enhancing, Aqua Culture, and Wardley's pellets. I mix my pellets with garlic and keep them in the fridge until the garlic dries out really good. I feed pellets probably 5-6 meals a week. I also feed frozen blood worms, brine shrimp, and glass worms, probably another 5-6 meals a week. I only feed freeze dried once or twice a week if at all.

Frozen brine shrimp, Frozen blood worm's, Frozen pea's once every 2 or 3 month's to help clean them out so they dont get backed up. And then i go 48 hour's without feeding so they can get cleaned out the pea help's clean them out and the 48 hour's give's them time to get everything out. I learned that from a thai breeder and it work's very well. Even if you dont feed them a frozen pea and you just go 48 hour's without feeding it still helps them a lot.

I used Wardley's for a long time. But I went to Hikari Bio-Gold. Now I am trying New Life Spectrum Betta Formula. I also feed a variety of Frozen foods to them, including Brine Shrimp, Daphnia, and Bloodworms.